The invention relates to trackballs used in laptop and other computers to, for example, control the movement of a cursor displayed on the computer screen. Indeed, the prior art to my invention comprises the conventional trackball and any of plurality of different known mechanical, optical and/or electrical arrangements for enabling the computer to track rotations of the ball in response to user manipulation of same and to translate the direction and extent of rotation into electrical signals that can be used to, for example, change the displayed position of the cursor.